RT5C348B Datasheet (RICOH electronics devices division)

RT5C348B, 4-wire Serial Interface

Symbol CE Item Chip enable Input Description The CE pin is used for interfacing with the CPU.

Should be held high to allow access to the CPU.

Incorporates a pull-down resistor.

Should be held low or open when the CPU is powered off.

Allows a maximum input voltage of 5.5v regardless of supply voltage

12345 OUTLINE ’11.04.13 4-wire Serial Interface Rx5C348A/B The Rx5C348A/B are CMOS real-time clock ICs connected to the CPU by four signal lines, CE, SCLK, SI, SO, and configured to perform serial transmission of time and calendar data to the CPU.

The periodic interrupt circuit is configured to generate interrupt signals with six selectable interrupts ranging from 0.5 seconds to 1 month.

The 2 alarm interrupt circuits generate interrupt signals at preset times.

As the oscillation circuit is d

RT5C348B Features

* Timekeeping supply voltage ranging from 1.45 to 5.5V Low power consumption Rx5C348A: 0.35µA TYP (0.8µA MAX) at VDD=3V Rx5C348B: 0.55µA TYP (1.0µA MAX) at VDD=3V Only four signal lines (CE, SCLK, SI, and SO) required for connection to the CPU. Maximum clock frequency of 2 MHz (with VDD = 5V) Time cou